Method of determining the total available heat of gaseous fuel.



H. F. SMITH METHOD OF DETERMINING THE TO'I'AL AVAILABLE HEAT OF G ASEOUSFUEL.

APPLICATION FILED SEPT- 20, 19I2.

Patented J uly 4, 1916.

H ARRY FORD SMITH, OF LEXINGTON, OHIO.

METHODOF DETERMINING THE TOTAL AVAILABLE HEAT OF GASEOUS FUEL.

To all cvhom it may concern:

Be it known that I, HARRY F. SMITH, a

citizen of the United States, residing at Lexington, in county ofRichland' and State of Ohio, have invented certain new and usefulImprovements in Methods of Determining the Total Available Heat ofGaseous Fuel, of which the following is a specification.

Thisinvention relates to an-improvement in the method for determiningthe total available heat of gaseous 'fuel, and the object is to providemeans for determining the quantity of heat available in gaseous fuelflowing through a main by procuring a quantity or sample of the gaseousfuel from the main, and ascertaining the total heat developed by thecombustion of the sample.

The ordinary method for determining the available heat of gas hasheretofore con'slsted in measuring a quantity of gas, reducing thisquantity to terms of accepted standard conditions of pressure andtemperature, then separately determining the heating value oi the gasper unit volume corrected to the same standard conditions of temperatureand pressure and multiplying the total volume of gas deviations fromstandard conditions ob-- served. In metering gas, for example assupplied to gas engines or other similar de mine very accurately theactual volume of,

vices, utilizing the gas at frequent intervals but'not uniformly,pulsations are set up in the gas main which interfere with a correctdetermination of the volume. Furthermore when an attempt is made to usethe simple forms of metering apparatus, such asPitot tube or Venturitube, compensation must be made not only for errors due to pulsations inthe main but-also for variations in the spe- 'cific, density of thegas'as determined by its composition. Furthermore in determiningtheheating value per unit volume of gas. similar diificulties areencountered. It is necessary not only to determine the total heatdeveloped by the combustion of the gas sample, but it is equallynecessary to deter- Specification of Letters Patent.

Patented- July 4, 1916.

Application filed September 20, 1912. Serial No; 721,416.

gas, and to apply suitable corrections for variations in temperature andpressure from accepted standard conditions. In the present invention,many of these difficulties have been eliminated, and as a result notonly can simpler appliances be used, but more accurate results'can beobtamed.

The invention consists, first, in securing a.

of gas flowing; and second, in determining the total heat contained inthe sample of gas. It is understood that the total available heat in thegas flowing through the main can be determined by multiplying thetotalheat in the sample taken by a number representing the ratio of thissample to the total volume of gas.

The drawing discloses an apparatus for carrying out the invention, butas this apparatus is only one form of a number which might be used incarrying out the invention, it is not the intention to limit the use ofthe invention to this particular type of apparatus.

'A, represents a housing or casing which is preferably made in twosections, and con nected between the sections is a-metal disk B. Thehousing or casing is adapted to be connected to a gas pipe, or main, notshown.

The metal disk or diaphragm B is located in the path of the gas current,the gas passing through the housing in the direction indicated by thearrow. The diaphragm is provided with a large number of perforations oropenings 1, 1, and we will assume, for example, that the diaphragmcontains two hundred (200) orifices, the total area of which issufiicient to pass the total volume of the gas whose heat is to bemeasured. It will be seen that each one of the 200 orifices will pass anequal amount of gas,

that is to say, each orifice will pass one-half of the one per cent. ofthe total volume of gas passing throu h the main.

pressure within the chamber D may always the chamber D, the front oropen end of the chamber is covered by an elastic diaphragm E which isfree to move, and which trans mits the pressure from the surroundingspace F to the space within the mclosure or chamber D. The closing ofthe end of the chamber D by thediaphragm E is necessary for maintainingthe pressure on each side of the orifice C the same at all times, as thedifference in pressure on the two sides of every other orifice in thediaphragm B.- It will be understood, that if there are any pulsations inpressure in the space F, that the pulsations will be transmitted equallyto each of the two hundred orifices, including also the orifice C.Therefore, whatever changes in rate of flow .may be caused by suchpulsations in pressure,"these changes will affect equally and in likemanner each one of the various orifices in the diaphragm. It is furtherto be noted, that if the volume of gas should be affected by changes intem perature or pressure that whatever efi'ect these difierencesmay'have will be transmitted equally to each one of the orifices inquestion. Furthermore any change in density or specific gravity of thegas, due to change in the composition of the gas, will affect inexactlyequal manner the flow of gas through each one of the variousorifices shown. In order that the flow of gas from the chamber D mayalways be just sufficient to maintain pressure Within the chamber D thatwill be exactly equal to the pressure in the chamber F, a valve 3 isattached to the diaphragm E, which is adapted to regulate the flow ofgas through the opening 4; in the tube or pipe 2; so that should thepressure within the chamber D become slightly greater than within thespace F, the diaphragm will move so asto draw the valve away from theopening 4 to permit the surplus ofgas to escape through the pipe 2.

On the other hand, should the pressure in the chamber D be, from anycause, less than that in the space F, the diaphragm E will move so as toclose to a reater or less ex-- tent-the valve 3 for restricting the flowof gas through the pipe 2, thereby permitting the pressure in thechamber D to again rise until it is equal to the pressure in the spaceF. By this or by any other suitable means, a sample of gas issecured.which is truly representative of the average heat value and compositionof the gas measured, and which bears a definite volumetric proportion tothe total volume of gas passing the apparatus.

In a diaphragm provided with. two hundred orifices the gas dischargedfrom one orifice would be one-half of one per cent. of

the total. It is to be noted that-1t is a inat- 'ter of entireindifference what-'Jthe'actual volume of the gas sample taken from themain island .ita is entirely unnecessary to the total heat may bedetermined and measured, but other methods of determining the total heatcould be adopted, which are familiar to those skilled in the art.

In the apparatus shown, H is a combustion chamber in which the gassample is burned with air. A burner 5 is connected to the pipe .6 forburning the gas in the co mbustion chamber. -A chamber K is formed abovethe combustion chamber through which the heat and products of combustionpass, in which chamber the heat and prodnets of combustion come intodirect contact with water to be heated, and the products of combustionare discharged at the top of the apparatus through an out-let T, at atemperature equal tr that of the infiowing water. In order that thecondition of the ingoing air, to be burned with the gas, may be the--same with respect to temperature and moisture as that of the outgoingproducts of combustion, a chamber L is provided through which theingoing air to the apparatus is brought into contact with water at thesame temperature asthat supplied to the chamber K. The air passingupward through the chamber L is fully saturated with moisture andbrought to the same temperature as that of the incoming Water. In thechamber H this air enters into combustion with the sample of gas and theheated products of combustion pass upward through the cham* ber K,imparting their heat to the water and being discharged at T under thesame conditions of temperature and moisture as obtained for the ingoingair. In this manner, the rise in temperature of the water passingthrough the chamber K in conjunction with the volume or weight of waterso passing determines the total heat developed by the combustion of thegas.

A pipe S constitutes a source of water supplyand-a valve chamber orcasing Q receives water from the pipe S. A pipe P is connected to thecasing Q for conducting the water to the heat-absorbing chamber K. Thewater is discharged through the casing of the apparatus N, and then downpassing through openings 6 in the bottom of the concentric partition 7which is located between charged into the top of the chamber K,

q through a pipe 8. A meter M, is connected y to the pipe'P formeasuring accurately the quantity of water-passing to the heat absorbingchamber K. A pipe 9 is connected to the supply pipe S for conductingWater to the chamber L, which water is not measured. A pipe 0 isconnected to the lower end of the chamber K for conducting the heatedwater from the chamber, and connected to the pipe is a measuringinstrument 10 for determining the temperature of the water.

Pipes P and 0 form a thermostatic arrangement whereby a constantdifference in temperature is maintained between the ingoing water andthe water discharged from the chamber K. The member 0 consists of a tubecapable of changing its length with heat, constructed preferably ofbrass or some similar ,metal through which the water discharged fromthechamber K passes. The

pipe P is constructed of the same metal, and

through which pipe the water is conducted to the chamber K. A valve Risconnected to the pipe 0 and passes freely through the valve casing Q, topermit of its movement. If the-temperature of the pipes O and P are thesame, there will be no movement of the valve R. For a given difi'erencein temperature between the pipesOand Pthere will be a definite openingof the valve R. Should the temperature of the pipe 0 become greater thanthe temperature of the pipe 1?, the pipe 0 would expand and open thevalve R wider so as to permit a greater quantity of water to flowthrough the pipe P; but on the contrary should the temperature of themember 0 be reduced, the valve B would be correspondingly closed andthereby reduce the quantity of water passing through the pipe P. By thismethod the quantity of water flowing through the apparatus is sogoverned as to maintain a constant temperature difference between theingoing and out-' going water. It clearly follows, therefore,

that this temperature difference multiplied tioned to the totaldevelopment of heat in the combustion chamber H, and this in turn isdirectly proportioned to the 'rate of flow of heat in potential form ascombustible gas through diaphragm A and chamber K. By suitablygraduating the dials of the meter M, readings can be obtained directlyin terms of heat units. It is not necessary that this method ofrecording the rate flow of heat units be employed. For example itmay bedeemed more desirable to know the rate of flow at any particular time,and in this case provision can be made for passing water at a constantrate through the chamber'K. In this case the difference in temperaturebe tween the discharged water and the ingoing water supply will bear adirect relationship to the heat developed at that particular moment inthe chamber H.

It is clear from a careful examination of the method proposed that notonly is the apparatus much simplified, but many difficult andcomplicated corrections are entirely avoided. For example, it isentirely unnecessary to know anything concerning the actual volume ofgas passing the diaphragm A. It isunnecessary to know anythingconcerning its specific heating value .per cubic foot. It is unnecessaryto make any corrections for temperature, pressure, or specific gravity.Likewise in determining the total heat available, all that is requiredis to measure the heat liberated by the combustion of the gas sampledelivered to the chamber H. As a practical consideration it will benoted that the quantity of heat available for use in the chamber H maybe larger than that which is ordinarily considered necessary to use inconnection with the determination of heat -value per cubic foot. It ISaccordingly possible to determine the total heat with great accuracy forthe rea son that any'small heat losses from the apparatus from-radiationor the like bear a much smaller proportion to the total heat than in thecase of the ordinary type of calorimeter for determining the heat valueper cubic foot. The advantages of this invention are obvious to anyonefamiliar with the art. It is seldom-necessary or desirable to know thevolume ofcombustible gas in cubic feet. For all engineering purposes itis necessary to determine from this volume the total heat available inthe gas. By'the present method, the necessity for making theintermediate determination in cubic feet and the similar determinationof heat value per cubic foot is entirely avoided. Furthermore, theapparatus as shown is quite inde- 115- pendent of the usual difficultiesconnected with metering gas. Pulsations in the gas pressure do notaffect the readings of the apparatus. Variations in temperature,pressure, and specific gravity, need not be con- 120 sidered as they donot enter into the determination in any way- Even a partial fouling ofthe various orifices by accumulations of dirt through the passage ofimpure gas would not materially affect the readings of1 l25 theapparatus. Each orifice would be passing the same kind .of gas, andwould be fouled in approximately the same'degree.

It is only essential that all of the orifices shown should be at anygiven time operating 130,

under the same conditions. In determining the total heat, the process ismaterially simplified for the reason that it is entirely unnecessary tomake any determination with respect to the volume of gas treated. Indetermining the heat per cubic foot of gas, it

is very important that the gas be accurately measured. Withthe apparatusin question it is not necessary to determine either the volume,temperature, pressure or specific "gravity of the gas sample deliveredto the heat-measuring device, and the total heat available in the gas isdetermined with much simpler apparatus, and With materially lessliability to error than with the methods that have heretofore beenemployed for this purpose. I

Having fully described the invention, what is desired to be secured byLetters Patent, is i 1. A, method of determining the total availableheat of gaseous fuel flowing through a main, consisting in separatingfrom the flowing stream in the main a stream proportional theretoWithout determining the actual volumeof either portion, of then burningthe proportional stream of flowing gas and determining the heat unitsthus developed, and multiplying the quangas sample from the liquid whichhas been heated by the products of combustion passing through theliquid. I

3. A method of determining the total available heat of gaseous fueldelivered through a main, consisting in procuring a sample of the gasfrom the main, which gas is a definite fraction of the total volume,burning the gas sample and passing the products of combustion through aliquid, and determining from the liquid the total heat developed by thecombustion of the gas sample. a

In testimony whereof i affix my signature,

in the presence of two Witnesses.

HARRY FQRD SMITH. Witnesses:

Geo. TROUT, THOMAS Cunn'rorr.

